As this type of technique, as shown in FIG. 28 of this application, Patent Literature 1 discloses a battery terminal connection connector 104 for connecting electric wires 100 to a battery post 103 of a battery terminal 102 of a battery 101. The battery terminal connection connector 104 includes a female connector housing 106 with a branch terminal 105 accommodated therein, and a male connector housing 108 for accommodating a connection terminal 107 connected to an end of the electric wires 100. In the branch terminal 105, an attachment hole 109 through which the battery post 103 can be inserted is formed. With this configuration, in order to attach the female connector housing 106 to the battery terminal 102 of the battery 101, the battery post 103 is inserted through the attachment hole 109 of the branch terminal 105 of the female connector housing 106 and then a nut 110 is screwed on the battery post 103.